Galaxy S IV: Samsung's 8-core processor explained

NEW DELHI: There were rumours that Galaxy S IV would come with an eight-core processor. While it looked implausible that a phone would launch with such a powerful processor when most of the computers run 4-core processors nowadays, the rumours turned out to be true.

Galaxy S IV is powered by an eight-core processor. This is for the international version because it is expected that the US version will be powered by a four-core Snapdragon processor made by Qualcomm.

But the way it happens with new technologies, the devil is in the details. The Exynos 5410, the processor that powers Galaxy S IV, may have eight cores but the phone will use only four at a time. The processor has two types of cores. Four cores are powered by ARM's A15 architecture. These are high-performance cores and run at 1.6GHz. The remaining four cores use A7 architecture. These are cores with extremely good power efficiency and run at 1.2GHz.

The technology used in Exynos 5410 is called big.LITTLE and Samsung has taken a licence for it from ARM. In actual use, Galaxy S IV will use A7 cores while handling light work. For example, if you are making a call, the phone is likely to be powered by A7 cores. But if you are playing a demanding 3D game, it will switch off A7 cores and use A15 cores. At no point of time, the phone will use all eight cores simultaneously.

Samsung claims that this technology provides users best balance of performance as well as battery life. An important detail to note is that A15 cores are very powerful and even if only four of them are used in Exynos 5410, it is enough to make the device one of the most powerful smartphones in the market when it starts selling.

A few months ago, Samsung has published a whitepaper on the technology. Authored by several senior Samsung engineers, the paper noted, "Samsung has adopted a different architecture, known as the big.LITTLE architecture of ARM, for its Exynos line of high performance CPUs, designed specifically for the mobile computing and communications platform. The big.LITTLE architecture combines multiple cores to create a CPU that can execute both high and low-intensity tasks in the most efficient manner."

Another interesting detail about Exynos 5410 is the graphics chip inside it. The phone uses three chips of PowerVR 544 cores. The PowerVR 544 chips are similar to PowerVR 543 chips used in iPhone 5 but Samsung is likely running the cores in Exynos at a higher speed. Theoretically, it is expected to make Galaxy S IV the fastest smartphone in terms of graphics performance. The powerful graphics chip will also help the phone deal with demanding 3D games in future.